A development blog of what Con Kolivas is doing with code at the moment with the emphasis on linux kernel, MuQSS, BFS and -ck.

Tuesday, 15 August 2017

linux-4.12-ck2, MuQSS version 0.160 for linux-4.12

Announcing
a new -ck release, 4.12-ck2 with the latest version of the Multiple
Queue Skiplist Scheduler, version 0.160. These are patches designed to
improve system responsiveness and interactivity with specific emphasis
on the desktop, but configurable for any workload.

linux-4.12-ck2

MuQSS

Sorry about the delay. I skipped announcing 4.12-ck1 as there was a lingering bug report from pf (thanks for extensive report!) and a config problem in it that rendered it unbootable without extra confg options.

MuQSS 0.160 updates

- Fixed race leading to crash on use of sched_setaffinity.

4.12-ck2 updates

- BFQ is now in mainline so it is no longer part of the patchset.- BFQ now enabled by default along with scsi multiqueue to enable booting with it by default.- Enable setting new kyber I/O scheduler as default as well (I recommend people use BFQ though.)- Removed the mandatory swap_full() flag in the swap sucks patch after reports saying it was unhelpful.

Paolo Valente developed bfq (I apologize, I have to give credit to his amazing work).

As of 4.12, bfq in mainline is strictly bfq-mq and not the single-queue iosched that ck has added out-of-tree. Patches for the single-queue elevator bfq-sq has added in the main bfq-mq repository and is probably planned for mainline 4.13.

I am experiencing the same broken suspend problem as mentioned earlier. The system wakes up and instantly freezes on the login screen. Keyboard, mouse etc unresponsive. Can't switch into tty either. Also nothing interesting shows up in journalctl. Only solution is hard reset.

You are free to follow relevant discussion in linux-block mailing list. The issue is not fixed yet in the upstream, but there are some patches circulating around, and some were merged into -pf making suspend-resume with blk-mq reliable.

I somehow managed to get my personal PKGBUILD for linux-pf into some shape so I can share it on the internet. You might wanna try using the AUR package https://github.com/pinkfluid/linux-mpf . It will autodetect your local CPU and build for that platform.